AB v Kent County Council

When a young asylum seeker claims to be under 18, a local authority may use an abbreviated assessment based on physical appearance and demeanour only where the case is sufficiently obvious. It need not complete every safeguard in a full R (B) v London Borough of Merton assessment merely for form. The authority must, however, recognise the substantial margin of error inherent in such material, consider relevant evidence and credibility, and give the claimant the benefit of any doubt. No universal 25-year threshold or fixed margin was prescribed. An assessment placing the claimant at 20–25, without acknowledging that margin or addressing relevant cultural and professional evidence, was unlawful.

AB, an Afghan national, arrived in the United Kingdom claiming to be 15. Kent County Council assessed him as aged 20–25 from his physical appearance and demeanour, treated him as an adult, and declined to provide accommodation and support under the Children Act 1989. The Home Office relied on the assessment and detained him before releasing him on bail.

AB sought judicial review, alleging procedural unfairness, failure to conduct a full Merton-compliant assessment, irrationality, inadequate reasons and factual error. The central issue was whether a local authority could lawfully use an abbreviated assessment and, in particular, how the margin of error and benefit of the doubt principles identified in BF (Eritrea) v Secretary of State for the Home Department [2019] EWCA Civ 872 applied.

Claim succeeded. Kent County Council’s abbreviated age assessment was unlawful. The court ordered a full Merton-compliant assessment, but declined to quash the existing assessment because it remained relevant material, subject to the limitations identified in the judgment.

1. Public law duty and applicable framework. A local authority deciding to treat a person claiming to be a child as an adult must make the inquiries necessary to reach an informed decision about age. Failure to do so is a public law error: Secretary of State for Education and Science v Tameside MBC [1977] 1 AC 1014. The Merton guidelines constitute minimum standards of inquiry and fairness.
2. Abbreviated assessments. A full assessment is not required in every case. Where it is very obvious that the person is an adult or child, prolonged inquiry may be unnecessary. An abbreviated assessment based on physical appearance and demeanour may therefore be legitimate. It must nevertheless account for the margin of error inherent in that form of assessment.
3. Benefit of the doubt. The margin-of-error principle from BF (Eritrea) v Secretary of State for the Home Department [2019] EWCA Civ 872 applies more broadly than to Home Office initial assessments. Where doubt remains whether the person is over 18, the claimant must receive the benefit of the doubt and a full assessment should follow. The court declined to prescribe a universal 25-year threshold or fixed margin for local authorities.
4. Application. The estimate of 20–25 was too close to the age boundary to justify treating the abbreviated assessment as determinative. The Council failed adequately to acknowledge the margin of error, address the cultural context of an Afghan claimant, evaluate conflicting professional evidence, determine credibility, or explain the significance of observations such as being comfortable in one’s body and irritated by questioning.
5. Further orders. The factual question of AB’s age was left for the Upper Tribunal. Permission to transfer that issue was granted to the extent necessary, and the parties were invited to agree directions.

This was a first-instance judicial review. On 20 August 2019, Nicklin J granted permission and interim relief requiring Kent County Council to accommodate AB. The present court determined the lawfulness of the assessment and directed that the factual age issue be transferred to the Upper Tribunal if necessary.